I am thinking of stepping into the active crossover world as I just do not have the know how and limited electrical experience of the best designers out there to even attempt building a crossover to suit my needs.
What are peoples thoughts on protecting high frequency drivers or is the whole point of going active to remove all the passive components from the circuit? What would you have to use if it were an option (links to ebay or whatever would be much appreciated to a newbie builder).
I'm thinking of trying a Dayton Audio 408 or perhaps better (cheaper) a T.racks x4 from Thomann as I only need 4 channels. Hopefully the quality and control is comparable on the cheaper one.
What are peoples thoughts on protecting high frequency drivers or is the whole point of going active to remove all the passive components from the circuit? What would you have to use if it were an option (links to ebay or whatever would be much appreciated to a newbie builder).
I'm thinking of trying a Dayton Audio 408 or perhaps better (cheaper) a T.racks x4 from Thomann as I only need 4 channels. Hopefully the quality and control is comparable on the cheaper one.
Some thoughts:
- Best to eliminate all components between the speaker and amp. Some reading: Protection cap for my precious new compression drivers? Any decent amp will have DC protection etc built-in, so the tweeters should be safe.
- Passive crossovers aren't so bad, but you'll definitely need a measurement mic. You can get started with that for less than £100.
- Whatever you do, make sure it's still reasonably user-friendly. I went from tri-amped w/DSP to passive 2-ways with some EQ built into the (digital) source. The system used to get used once a week, with preference for playing music out of my laptop's built-in speakers. These days, the stereo is playing for about 10 hours per day. Much better.
- This is worth a look: ZOUDIO electronics
Chris
- Best to eliminate all components between the speaker and amp. Some reading: Protection cap for my precious new compression drivers? Any decent amp will have DC protection etc built-in, so the tweeters should be safe.
- Passive crossovers aren't so bad, but you'll definitely need a measurement mic. You can get started with that for less than £100.
- Whatever you do, make sure it's still reasonably user-friendly. I went from tri-amped w/DSP to passive 2-ways with some EQ built into the (digital) source. The system used to get used once a week, with preference for playing music out of my laptop's built-in speakers. These days, the stereo is playing for about 10 hours per day. Much better.
- This is worth a look: ZOUDIO electronics
Chris
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Thanks Chris
Big wow.
That amp looks amazing! Even though I cant find any power specs or anything on it. But its an amp DSP all in one and still working out cheaper than the cheapest DSP unit I can find.
When you say decent amps as well I am literally just using cheap DIY class D to get me the number of amps I need to achieve DSP control.
And I am with you I have nothing against passive crossovers they are the way I would go if I had the choice. Unfortunately though I'm nowhere near able to build one that tailors the sound like some of the best are capable of and match drivers, levels and frequency response and then make final adjustments to really make the speakers sing. But DSP and a decent mic that is all within my reach. I can get a near flattish response integrate drivers and then tune to my liking. A load of resistors and coils I would have no chance and not even know where to start even with the best measurement device in the world.
As for measurement, I am building myself up to a bit of outlay for perhaps a Dayton Audio Omnimic V2. It seems to be one of the best and easiest out of the box intuitive designs I can find, and it even has the ability to make changes in real time with the continuous sweeps where adjustment can be made and seen instantly on the graph as you go. I tried the UMIK1 a while back with the free REW software and it was a bit clunky I thought, but perhaps I should have spent more time with it. The Dayton just seems better though all round if I can part with the money 🙂
Big wow.
That amp looks amazing! Even though I cant find any power specs or anything on it. But its an amp DSP all in one and still working out cheaper than the cheapest DSP unit I can find.
When you say decent amps as well I am literally just using cheap DIY class D to get me the number of amps I need to achieve DSP control.
And I am with you I have nothing against passive crossovers they are the way I would go if I had the choice. Unfortunately though I'm nowhere near able to build one that tailors the sound like some of the best are capable of and match drivers, levels and frequency response and then make final adjustments to really make the speakers sing. But DSP and a decent mic that is all within my reach. I can get a near flattish response integrate drivers and then tune to my liking. A load of resistors and coils I would have no chance and not even know where to start even with the best measurement device in the world.
As for measurement, I am building myself up to a bit of outlay for perhaps a Dayton Audio Omnimic V2. It seems to be one of the best and easiest out of the box intuitive designs I can find, and it even has the ability to make changes in real time with the continuous sweeps where adjustment can be made and seen instantly on the graph as you go. I tried the UMIK1 a while back with the free REW software and it was a bit clunky I thought, but perhaps I should have spent more time with it. The Dayton just seems better though all round if I can part with the money 🙂
DIY people need tweeter protection capacitors for screw-ups.
Commercial active speakers usually come without.
Commercial active speakers usually come without.
The worry is not the amp failing and sending DC to the tweeter, it's the operator having a brain fart and disabling the crossover to the tweeter amp, or accidentally swapping the signal cables between the DSP and the woofer/tweeter amps, or unexpected impulses such as a bad signal connection or equipment suddenly losing power, causing loud pops and bangs to be sent to the tweeter. I've also had a case of a MiniDSP having it's memory randomly corrupt after several years of constant use... Luckily the MiniDSP just booted up with the outputs disabled, not sure if that is by design or just good luck.
I run a single series capacitor with each of my tweeters. Highpass frequency due to the cap is circa 300Hz. The effect is essentially inaudible given my tweeters cross at 2kHz. You can run fancy poly-put-the-kettle-on caps if it makes you feel better (but it won't make a difference 🙂)
Will it prevent them blowing up if I run my DSP fullrange into the tweeter amps and crank the volume to the max? Probably not, but it at least will take the very low frequency content out of unexpected impulses, giving the tweeters a good chance of survival.
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Adding a cap is relatively straightforward. It assists with louder measurement sweeps and since measuring with it in place accounts for it.
I've been using minidsp and 3 amps for a couple of years now. All are branded amps so I dont bother with any protection. If you go the DIY amllifier board route I would def recomend some protection boards as well.
I dont know why people baby tweeters so much. A soft dome can be swept full pelt without being damaged so some gentle on off pops are negligible.
I moved from soft dome to compression driver this year and put an Lpad in but aside from that I agree with Chris.
I dont know why people baby tweeters so much. A soft dome can be swept full pelt without being damaged so some gentle on off pops are negligible.
I moved from soft dome to compression driver this year and put an Lpad in but aside from that I agree with Chris.
Cheers thats interesting about sweeping soft domes, I didnt know that. Just putting the question out there to see what peoples thought were.
How expensive are your tweeters and can they be easily replaced??
If the answer is very or no use a cap
Rob 🙂
If the answer is very or no use a cap
Rob 🙂
Actually I did loose a woofer because I put phantom power through it by mistake. But I took that as a lesson and a good reason to build a new speakers.
Yes I get this Rob. Tweeters, well some tweeters can be expensive if they did go pop for some reasons, be it a glitch in the software, bass getting through, amp pop or whatever it could cost a bit to replace one. All your effort gone on your build and where protection could have saved it (possibly), this is why I'm asking, and what should be used for protrction?
Remember that even inexpensive tweeters become unobtanium at seemingly random points in time.
A good rule of thumb for a simple protection cap is: three octaves below crossover(give or take), one octave from resonance peak(unless an unusually smooth impedance), calculate with impedance at frequency.
Fudge away, but a good starting point.
A good rule of thumb for a simple protection cap is: three octaves below crossover(give or take), one octave from resonance peak(unless an unusually smooth impedance), calculate with impedance at frequency.
Fudge away, but a good starting point.
Phantom power shouldn't kill woofers, or indeed any speaker. +48v DC, sure, but most preamps will only supply 10mA maximum - certainly not enough to cause any problems.
Chris
PS - I agree that people seem to baby tweeters a bit. I've had my 18Sound ND1460s hammering the phase plugs (HPF wasn't implemented properly), and they came out fine.
It might be worth considering a 6 channel DSP in case you decide to build a 3 way pair of speakers or add subs at a later date.
I've been using Behringer DCX's for ages (about 17 years I think) and have had lots of different tweeters attached to lots of different pro amps and never had one blow. However, it has always been at the back of my mind that one of my amps could develop a fault and blow them, so maybe a protection cap should be on my list for my current project.
What response are you wanting, size, type or brand?
Incidentally I have soft turn on for my tweeter amp and DC protection with transformers yet I still want to protect from glitches before the amp. I incorporate high pass elements into the amp itself.
Completely agree; I know my ability to hose stuff up so the cap in series with the tweeter is just cheap; good insurance.
The tweeter is a Beyma TPL-75 and the capacitor is a Solen 47uf in parallel with some other smaller value (2.2uF Multicap I think so yeah; poly-put-the-kettle-on 😀).